r* 
( 6 ) 
ken on the Meridian from the Equator, fliews the 
Latitude ; and the Minutes reckoned on the Equator 
from the Meridian to C, the Time of the firft Ob* 
fervation, fhew the Hour, 
The Interval in Time or Degree between the two 
Places, fhewn by the Index G, is the Difference of 
Longitude. 
JV. B . Thofe Obfervations are beff,whofe Arches 
crofs each other almofl at right Angles. 
II. PUOPOSITIO N. 
The Zenith Ttiftances of two Stars, obferved at 
the fame Time , their ^Declination , and right Afi 
cenfion being known ; to find the Latitude of the 
Tlace of Ob fervation. 
Fix the Center of the Beam-compafs to the Decli- 
nation of either of the Stars, and with the Zenith Di- 
fiance of that Star defcribe an Arch ; move the 
Meridian as many Hours farther as is the Difference 
of right Afcenfion of the other Star ; and fix the 
Center of the Beam-compafs to the Declination of itj 
and with its Zenith Diffance crofs the firft Arch : 
The Interfe&ion fhews the Latitude of the Place of 
Obfervation ,* and alfo the Diftance of the right Af 
cenfion of the Zenith from that of either of the Stars, 
by which means the Hour may be known. 
If a Celeftial Globe is made ufe of, then place 
the Center of the Beam compafs over the feveral 
Stars. 
The 
I 
